Thermoelectric safety shutoff device



Sep- 22, 1942 H. F. ALFERY 2,296,322

THERMOELECTRIC SAFETY SHUTOFF DEVICE Filed Nov. 9, 1959 2 Sheets-Sheet lSept 22 1942- H. F. ALFERY 2,296,322

THERMOELECTRIC SAFETY SHUTOFF DEVICE 2 Sheets-Sheet 2 Filed Nov. 9, 1939Patented Sept. 22, 1942 Henry F. Alfery, Milwaukee, Wis., assigner toMilwaukee Gas Speciality Company, Milwaukee, Wis., a corporation ofWisconsin .pplication November Si, 1939, Serial No. 303,601

3 Clas.

This invention relates to safety devices for heating and other apparatusand has particular relation to an improved thermoelectric valve forautomatically shutting off the fuel supply for a burner uponextinguishment of a pilot light or other flame.

The present invention is a `continuation in part of my copendingapplication Serial No. 186,967, led January 26, 1938, and now Patent No.2,276,909, granted Mar. 17, 1942.

The illustrated embodiment of the invention comprises generally a valveadapted to be positioned, for instance, in the fuel supply line leadingto the burner, an electromagnet, an armature for the electromagnetwhich, when attracted, is

adapted to maintain or to permit the valve to be maintained in open oroperating position, and when retracted, compels closing of the valve toshut off the supply of fuel to the burner, and a thermocouple adapted tobe placed in position to be heated by a pilot light or other flame andconnected in circuit with the electromagnet.

One of the main objects of the present invention is to provide animproved quick detachable connection between the lead conductors for thethermocouple and thethermoelectric safety device. l

It is also an object of the invention to provide means for shutting o orinterrupting the ow of fuel to the main burner during the operation ofresetting the armature to attracted position and the thermoelectrievalve to open position-or other thermoelectric control means tooperating position-and, in conjunction therewith, means for by-passingfuel, for instance, for the pilot burner while the ow of fuel for themain burner is thus interrupted during the resetting operation andwherein, at the same time, the thermoelectric valve operates to shut onot only the supply of fuel to the main burner, but also the sulpply offuel for the pilot burner when the pilot burner or other name, to theheat of which the thermocouple is subjected, is extinguished.

Another object of the invention is to provide an improved electromagnetassembly and mounting therefor, and more specifically, an improvedelectromagnet assembly lhaving guide means for the armature adapted toconstitute a part of such assembly and having also quick detachableconnector means constituting a part of the electromagnet assembly andadapted, when the electromagnet assembly is mounted within the enclosuretherefor, to project from the electromagnet enclosure for quickdetachable connection with the quick detachable connector means on thethermocouple leads.

Further objects and advantages of the invention will be apparent fromthe following detailed description, takenA in connection withtheaccompanying drawings, in lwhich:

Figure 1 is a vertical section through a thermoelectric valve embodyingthe present invention; Figure 2 is a sectional view taken on the line 22 of Figure 1;

Figure 3 is a fragmentary vertical section partially in elevation andshowing the quick detachable connector means on the thennocouple leadsconnected with the quick detachable connector means on thethermoelectric valve; and

Figure i is a fragmentary elevational view showing the quick detachableconnector means on the thermocouple leads.

The device is shown as a thermoelectric safety shutoff valve forshutting off the supplyvof fuel tothe burner, which, for instance, maybe the burner for a room, oven, or other space heater. or the burner fora water heater, conversion heater, or any other burner.

The device selected for illustration comprises a valve body i@ having afuel inlet il and a fuel outlet l2 which are tapped internally toreceive the inlet and outlet pipe sectionsifi and i6, respectively. Theinlet pipe section receives the fuel from a suitable source of fuelsupply, and the outlet pipe section leads to the burner.

The valve body has an internal wall or partition l5 which has a valveopening i6 through which communication is adapted to be eifected betweenthe inlet chamber i8, which is in communication with the inlet li, andthe outlet chamber i9, which is in communication with the outlet i2.Communication between the inlet chamber i9 and the outlet chamber I9through the opening it is controlled by al valvevmember 25 shown asadapted to seat upon the Valve seat 25', preferably in a direction withthe flow of gas or other fuel, the arrow 26 indicating the direction ofow of the fuel. The valve member 25 is held to the inner end of thevalve stem 28, for instance, by a U-shaped fastener, snap ring, or

other fastener means indicated at 29. The particular valve disc shown inthe drawings has a valve disc gasket or yielding seating material 3Usecured thereto by a valve disc screw 32, an intervening Washer beingshown at 36. These features may vary within the scope of the presentinvention.

The hood and cup assembly which encloses the electromagnet and armaturefor the thermoelecl pressed fit or is otherwise suitably secured in theinner end oi the -hood 35, and encloses and sealsv the interior of thehood'from the deleterious ac.- tion of the gas or other fuel whichpasses through the valve body. The hood 55 is clamped to the valve bodyi8 by a union nut 42, with the hood and cup assembly closing the opening44'in the valve body. A union gasket may be provided at 45. I

The electromagnet, which is sealed within the hood and cup assemblycomprises a magnet frame 50 shown in the drawings as of U-shaped form,although this may vary widely. The magnet frame 55 is secured at 52, andis supported by a metallic plate 54. A metallicv terminal stud 55 havingan enlarged outer end at 55 and a reduced stem l extending inwardlytherefrom fits in a correspondingly formed metallic bushing 58. Ametallic washer 59 underlies the adjacent portion of t-he plate 55 andis secured with the plate 54 to the bushing 58 and lstud 55, forinstance, by extending the reduced inner end of the stud 55 through thewasher 59 and heading the inner end of the stud over as indicated at 50,or otherwise as desired. The stud, which is thereby secured to the plate54 with the bushing 55 so that these parts constitute a unitaryassembly, is insulated from the bushing 55 by insulation indicated at52. The washer 59 isv insulated from the platei 54 by insulationindicated, at 58.

The bushing55, with the stud 55 secured therein as set iorth, extendsoutwardly through an opening 55 in the outer end of the hood 35. Thebushing 58 is externally threaded, and a nut '55 threaded thereon clampsthe bushing and stud assembly in place in the opening 55. Screws` 60 orother suitable means may be employed for additionally securing the plate54 to the outer end of the 'hood 35. Packing may, if desired, beinterposed between the plate 54 and the outer e'nd wall of the hood 36as indicated at 55. If desired, the bushing 58 may be grounded tothehood 35.

` One terminal of the magnet coil 10, which is shown as surrounding oneof the legs of the magnet frame 50, is connected at 12 to the terminalstud 55. The other terminal of the coil 'I0 is connected at 'i3 totheplate 54, and through the plate 54 to the terminal bushing 58.

One of the terminals of the-coil 'I0 is adapted to be connected incircuit with one of the thermocouple leads through the stud 55, andwhere the bushing 58 is insulated from the hood 35, the other terminalof the coil I5 is adapted to be connected in circuit with the otherthermocouple lead through the bushing 55. Where the bushing 58 isgrounded to the hood, this side of the thermoelectric circuit iscompleted by grounding one side of the thermocouple and one of theterminals of the coil l5, for instance, to the hood 36. The enlarged outer end of the stud 55 has a conical recess l5. l

Insulating strips are provided at 80 and 82, and

' an insulating strip 53 is provided Vbetween one side of the coil 'i0and the adjacent leg of the magnet frame 50. The insulating strips 80and 52 have openings through which the legs of the magnet frame extend,and underlying the insulating strip 52 is an amature guide 84 which maybe formed of metal or other suitable mate- 55, and screws 55, one ateach of the opposite sides of the electromagnet, have their headsengaging the flange and their shanks extending through registeringopenings in the insulating strips and 82 and threaded at their outerends in the depressed -portion oi the plate 54. The screws hold theinsulating strip 82 and annature guide 84 in place so that these parts,with the magnet frame 55, coil l0, insulatingstrips 80 and 82, plate 54,Aand the stud and bushing terminal connector, constitute a unitaryassembly which, upon being positioned within the cup 36 is adapted to besecured in place therein by the nut 55 and screws 68, only one of whichlat- I ter screws is shown.

'Ihe armature 90 has attached thereto by upwardly extending bent-overportions 8| a. cradle 92 which, in turn, is connected to the upper orouter end of the valve stem 28, preferably for limited universalmovement, for instance by means of U-shaped retainers 93 engaginggrooves in the upper end of the valve stem 28. The armature is guidedfor reciprocatory movement by the armature guides 84, and the attachmentof the valve member 25 to the lower end of the stem 28 preferably allowslimited universal movement with respect to the stem. This limiteduniversal movement oi' the armature and valve on the stem 28 permitsself-accommodation of the armature to the pole ends of the magnet frameand self-accommodation of the valve member 25 to its seat 25.

For the purpose of resetting the valve 25 to open position and thearmature 90 to attracted position against the pole ends of the magnetframe 50 after the coil I0 is deenergized or after it becomesinsuiliciently energized to hold the armature in attracted position. aresetting stem |00.is mounted for sliding movement in the valve body I0in axial alignment with the valve 25. Secured upon the lower end of the.stem |00 is a reset button I0|, and ilxed upon the upper end the pilotburner (not shown).

the passageway I I2 may be closed at I I4. This of the stem is a valvemember |02. The valve member 02 has a depending annular flange or rib|03 which engages the packing'l04 and presses the same tightly aroundthe stem |00 to prevent leakage of gas or other fuel out along the stem.The packing |04 is carried by a gland member |05 mounted in the opening|05, and this opening is sealed against the leakage of gas by suitablepacking indicated at |08. A washer is provided at |09, and surroundingthe stem |00 and interposed between the washer |09 and the reset button|0I is a coiled spring ||0 which normally maintains the flow interruptervalve |02 in open position, as shown, and the reset button |0| inoutwardly projected position.

Opening laterally from the valve opening I5 intermediate the endsthereof is a passageway ||2 which is connected to a tube or fuel supplypipe 3 for delivering gaseous or other fuel to The outer end of positionclosing oif communication from the inlet rial. The outer end of theguide 54 has a ilange 75 chamber I8 to the outlet chamber I9 through thevalve opening I6 during the resetting operation. At the same time, thepassageway 2 is so disposed that the valve member 25 operates to shutoil' not vonly the supply of gaseous fuel= to the main burner, but alsothe supply of gaseous fuel to the pilot burner when the valve member 25is closed against itsseat 25'.

The thermocouple is shown by way of illustration and not by way oflimitation as of the general character disclosed and claimed in Oscar J.Leins Patent No. 2,126,564, granted August 9, 1938. The thermocouplecomprises an outer tubular metallic thermocouple member |20 and an innermetallic thermocouple member I2| joined at one end to the end of theouter thermocouple member to form the thermal junction |22 which isplaced, for instance, in position to be heated by the pilot light or anyother desired name. An inner lead conductor |23 is joined to the innerthermocouple member to form an internal thermal junction |24, and anouter tubular lead conductor |25 is connected to the outer thermocouplemember |20, for instance through a sleeve |26 to form a third thermaljunction |28. rI Che outer lead conductor |25 encloses the inner leadconductor |23, and with the outer thermccoupe member and the sleeve |26constitutes an enclosure about the inner thermocouple member and theinner lead conductor and the inner thermocouple junction |20. The innerlead conductor |23 is insulated from the outer lead conductor, forinstance, by a Wrapping of insulation on the inner lead conductor asindicated at |26.

The free end of the inner thermocouple lead |23 extends from theadjacent end of the outer lead |25 and has xed thereon and in goodconducting contact therewith a wedge member or metallic connector cone|30. The outer lead conductor |25 may have fixed thereon a metallicconnector sleeve |32 in good conducting contact therewith. The sleeve|32 is insulated from the cone |30 by insulation indicated at |34. Acouple lead connector nut is provided at |36, this nut having aninternal shoulder which cooperates with a shoulder on the sleeve |32.

By applying the connector means on the thermocople leads to theconnector terminal means on the thermoelectric safety valve with thecone |30 positioned in the recess l5 and threading the nut |36 upon thebushing 58, the cone |30 is wedged into the recess l5, and consequentlymakes good positive Contact with the stud 55, thereby connecting thelead |23 with one terminal of the coil l0. At the same time, thethreaded engagement between the nut |35 and the bushing 58 together withthe clamping of the nut |35 against the connector sleeve |32 forms agoed positive connection between the adjacent end of the lead |25 andthe bushing 58, thereby connecting the lead |25 to the other terminal ofthe coil 70. The thermocouple leads are quickly disconnected from thedevice by unscrewing the nut |36 from the bushing 50, and the connectionis made quickly in the manner set forth.

Theoperation of the device is as follows:

When it is desired to ignite the main burner or other burner suppliedwith iuel from the outlet |2, the reset button is pushed manually in aninward or upward direction. This moves the valve member 25 to openposition away from the seat and the armature 90 into attracted positionengaging the pole ends of the magnet frame 50. In this raised positionof the reset stem |00, the ilow interrupter valve |02 enters the valveopening |6 and shuts off communication between the inlet chamber |8 andthe outlet chamber l through the opening I5 and thereby the liow of fuelto the main burner to prevent the escape of gaseous fuel from the mainburner during the resetting operation.

The valve member 25 is open, however, at this time, and the passagewayH2, by-passing the coA A|22 subject to the heat of the pilot Iiame and,

as a result, the pilot name energizes the thermocouple, creating athermoelectric current which energizes the coil l0 and causes the.armature 00 to be held in attracted position and the valve 25 to beheld in open position against the tension of the spring' |20. The resetbutton |0| may then be released, and the spring H0 moves the stem |00downwardly to the position shown in Figure 1, and with it the valve |02to open position.

The gaseous fuel then flows through the valve opening |6 and out throughthe fuel supply line I4 to the feed pipe to which air is admitted, andthe gaseous mixture enters the main burner where it is ignited by thepilot burner as it issues from the ports of the m'ain burner. In casethe main burner is accidentally extinguished, the pilot burner willreignite thesame, and thereby assures that the main burner is lighted aslong as fuel is supplied thereto.

If the pilot burner is extinguished, the thermoelectric current throughthe coil 10 diminishes to such an extent that the armature is released,whereupon the spring |40 forces the valve member 25 into engagement withthe seat 25', thereby shutting oi the ow of fuel to the mail! burner andto the pilot burner.

The bottom wall of the cup 40 is shown as depressed at |4I and providedwith an opening |42 in which the stem 28 has reciprocatory movement. Theopening-|42 is sealed against the leakage of gas or other fuel from thebody 0 into the electromagnet enclosure by suitable packing indicated at|43. A washer is provided at |45, and the spring |40 surrounds the valvestem 28 and is interposed between the washer |25 and the valve member25. The spring |40, which is shown as of generally conical form, inaddition to moving the valve 25 to closed position and the armature 90to retracted position upon extinguishment of the iiame, compresses thepacking |03 tightly about the stem 20 to prevent leakage of fuel intothe hood and cup assembly.

The pilot fuel supply passageway H3 extends out at |70 from oppositesides of the valve body as indicated in Figure 2, and the diametricallyopposite outlets of this passageway are provided with screw plugs |2. Byremoving either plug |12, the pilot supply tube may be connected toeither side of the valve body as desired.

I do not intend to be limited to the precise details vshown ordescribed.

I claim:

1. In a device of the class described, a valve body having an inlet andan outlet and means dening a passage between said inlet and said outlet,a pilot outlet leading from said passage, shutoff valve means operableto closed position anterior of said pilot outlet to shut oi the flowthrough said iirst outlet and said pilot outlet, reset means cooperablewith said shutoff valve means for actuating said shutoff valve means toopen position, and a second valve actuated to closed position posteriorof said pilot outlet by the resetting operation of said reset means toshut oi the flow through said first outlet without shutting off the flowthrough the pilot outlet dur-i ing the resetting operation, said secondvalve inlet and outlet for permitting continued resetting movement afterthe iiow through said ilrst outlet is shut oir by said second valve.

2. In a. device oi' the class described, a'valve.

body havingl an inlet and an outlet, a partition wall disposed betweensaid inlet and outlet and having a valve seat on one side of said walland a valve passage opening through said wall, a shutoff valve memberoperableto closed position engaging said valve seat to 'shut oi! fluidnow through said outlet, a reset plunger adapted to be projectedinwardly to reset said shutot! valve to open position, and a. valvemember ilxed on said reset plunger and cooperable with the passage insaid partition wall to shut oil' the ilow through said outlet during theresetting operation and by movement in said passage permitting resetting movement alter the flow through said outlet is shut om by saidsecond valve member modena and without relative movement between saidseeond valve member and said reset plunger.

3. In s device ci' the class described, a valve body having an inlet andan outlet and means defining a e between said inlet and nid outlet, ashutoi! valve member operable to closed position to shut oil.r the nowthrough said outlet, reset means cooperable with said shutoff valvemember for actuating saidshutoff valve member to open position, and aseeond valve member lctuated to closed position by the resettingoperation of said reset 'means to shut oi! the flow through said outletduring the resetting opera-` tion, said second valve member havingmovable dt -in the e between the inlet and outlet for permittingcontinued resetting -Y movement aiter the new through said outlet isshut oi! by said vsecond valve member.

` HENRY F. ALF'ERY.

